Tripoli , Libya -LRB- CNN -RRB- -- Fighting continued Monday as rival Libyan militias battled for Tripoli International Airport and the interim government said it was considering asking for international military help .

In a statement aired on a private Libyan television channel , one of the three main Zintan groups in Tripoli said that at least two members of the force defending positions at the airport were killed in a rocket attack . Al-Qaaqaa brigade said at least three other people were wounded .

A photo posted on several Zintan Facebook pages showed a makeshift clinic set up inside the airport 's main terminal .

CNN could not independently verify when the image was taken .

The government in a written statement said early Tuesday that it discussed at an emergency session `` a potential request for international forces to solidify the state 's capabilities '' at an emergency session .

While Libyan officials have called for calm , the government is weak and militias outnumber and outgun its security forces . Many of the armed groups are on the state 's payroll .

These circumstances make it very difficult for the government to gain control over this latest increasingly volatile and violent situation .

Still the government on Tuesday called for an immediate halt to the fighting and for the militias to withdraw within a week at least 20 kilometers -LRB- 12 miles -RRB- from the airport . It said any commander that orders attacks on civilian facilities , including the airport , will face charges of murder .

A resident who lives near the airport told CNN families in the area are fearful they will be killed or injured by what appears to them as indiscriminate shelling .

The Libyan government statement said peacekeepers might give it a chance to build a suitable army and police force .

More rocket attacks

Local media reported earlier Monday that rockets had hit the airport . A CNN crew could hear sporadic gunfire and explosions in the direction of the airport .

The government said the customs building , maintenance building and some national security department planes had been destroyed . It also said 90 % of the airliners parked there had been damaged as had the control tower . The damage to the planes , many of which belong to the two national airlines , is in the hundreds of millions of dollars , the government said .

The United Nations announced that it had evacuated its staff .

`` This is a temporary measure , '' the United Nations said in a written statement . `` Staff will return as soon as security conditions permit . The United Nations , which stood by the Libyan people in their revolution in 2011 , will not abandon them as they seek to build a democratic state . ''

It was the first time the U.N. staff in Tripoli had left since the revolution .

The U.S. embassy updated its security message for Americans in the country , cautioning them to stay away from the airport , Airport Road and another nearby street . It said it could only provide limited emergency services to U.S. citizens .

No air traffic

All flights in and out of the airport have been suspended .

Brigades from the Zintan militia have controlled the airport since the Libyan civil war in 2011 . Other militias have tried to wrest control of the airport from the Zintan brigades for years .

Armed vehicles gathered in the area overnight before fighting broke out around dawn Sunday , witnesses said . Nine people were killed that day and 25 others wounded , the government said .

Tensions remain

Even though Libyans successfully toppled the 42-year rule of Moammar Gadhafi in 2011 , the country is far from stable . Armed militias are now the biggest challenge .

The international community has largely agreed that the key to resolving Libya 's crisis is national dialogue . But a weak central government -- combined with militias split along regional , tribal and ideological lines -- has added to the challenge .

The U.S. State Department said this past weekend it was concerned the fighting could lead to widespread conflict and backed the new government .

`` We affirm our support for Libya 's democratic transition and urge the seating of the new Council of Representatives as soon as possible , '' the statement added . `` Finally , we stress the vital role Libya 's Constitution Drafting Assembly plays in building the new country for which Libyans sacrificed so much during the revolution . ''

CNN 's Ashley Fantz contributed to this report .

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NEW : Government says commanders who fire on civilian buildings will face charges

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Rockets reportedly struck the airport and at least two people were killed

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Libyan government says it may request international troops to help stop the violence

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U.N. removes its staff in Tripoli for first time since revolution